Output feedback and under-voltage detection system

• US 20040195976A1
• Filed: 04/20/2004
• Published: 10/07/2004
• Est. Priority Date: 11/16/1998
• Status: Active Grant

• Current Assignee: Alex Dienguerian, Balu Balakrishnan, Leif O. Lund
• Original Assignee: Alex Dienguerian, Balu Balakrishnan, Leif O. Lund
• Inventors: Lund, Leif, Balakrishnan, Balu, Dienguerian, Alex
• Granted Patent: US 7,663,852 B2
• Time in Patent Office: Days
• US Class Current: 315/224
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence

Abstract

A switched mode controller for properly handling an under-voltage condition in a power line which includes a current mirror for receiving current from the power line; a reference current source coupled to the current mirror for supplying a reference current; and a power transistor coupled to the reference current source, the power transistor generating a pulse width modulated signal when current from the power line exceeds the reference current, the power transistor being disabled when current from the power line is less than the reference current.

Claims

1-42. -42 (Canceled).

43. A method, comprising:

alternatingly disabling and enabling a power supply when the power supply is experiencing a fault condition;

continuing the alternating disabling and enabling of the power supply until the fault condition is removed; and

detecting an input under-voltage condition when the power supply is disabled during said alternatingly disabling and enabling the power supply when the power supply is experiencing the fault condition.

44. The method of claim 43 further comprising preventing the power supply from being enabled following the detection of the input under-voltage condition until the input under-voltage condition is removed.

45. The method of claim 43 further comprising detecting the input under-voltage condition during power-up of the power supply.